Purpose: :
The development of corneal cross-linking procedures for therat eye requires knowledge of anterior segment biometry andUV transmittance characteristics for the cornea and lens. Thepurpose of this research was to make direct measurements ofanterior segment biometry and spectral transmittance propertiesof the cornea and lens in the adult Brown Norway rat.

Methods: :
Biometric measurements were performed using OCT and in vivoconfocal microscopy imaging of the anterior segment prior toocular dissection. Circumlimbal corneal excision and lens removalwas performed on 6 eyes of 4 aged adult Brown Norway rats (18mo). Excised tissue was immediately mounted normal to a 0.6mm diameter parallel light beam from a fiber optic light source(Ocean Optics DH2000) with the front end of a detecting fiberplaced directly behind the test tissue coupling the light tofiber optic spectrometer (Ocean Optics USB4000). The spectraltransmittance of test lenses and corneas (n=6), with and withoutepithelium, could therefore be determined from 250-700 nm.

Conclusions: :
Total central corneal thickness, epithelial thickness, and endothelialcell density measurements agree well with previous reports ofcorneal biometry in the aged rat. The cornea and lens of theadult brown Norway rat do transmit light >325 nm and passageof shorter wavelengths is limited by the lens. The cornea willtransmit light >290 nm and with the epithelium removed, thecornea will pass wavelengths as short as 250 nm. This UV transmittancedata combined with estimates of corneal thickness and endothelialcell density will help develop a model for corneal crosslinkingin the rat eye.